Which of the following is an example of feedback allosteric inhibition?
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(A)
Inhibition of the first enzyme in a pathway by the end product.
2
Reliable marker of myocardial infarction is:
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(C)
CK-2
3
What is the role of the enzyme, Trypsin?
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(C)
Digestion of proteins and polypeptides in the small intestine
4
In feedback inhibition, the end product of a metabolic pathway typically acts as a(n):
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(B)
Inhibitor of the first enzyme.
5
What is the role of ATP in some enzyme reactions?
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(B)
It provides energy.
6
What is the major clinical application of the enzyme Collagenase?
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(B)
Removing dead tissue from wounds
7
Which of the following is NOT a characteristic of enzymes?
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(B)
They are consumed in the reaction.
8
What is the name of the model that explains that an enzyme has a rigid shape, like a lock?
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(B)
Lock and key model
9
The enzyme useful in the treatment of leukemia is:
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(B)
Asparaginase
10
What are the main features of competitive inhibitors?
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A
B
C
11
A competitive inhibitor:
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(A)
Binds to the active site.
12
Which of the following is NOT an example of an enzyme used in clinical diagnostics?
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(D)
Trypsin
13
Which type of enzyme inhibitor binds to a site distinct from the active site and, upon binding, alters the enzyme's conformation and catalytic activity?
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(B)
Noncompetitive
14
Which of the following is an example of a mechanism-based inhibitor?
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(B)
Penicillin
15
Transaminases enzyme belong to the class:
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(B)
Transferases
16
What is the primary function of the enzyme, Amylase?
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(C)
Digestion of carbohydrates (starch).
17
What is the role of a catalyst?
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(C)
To speed up a reaction without being consumed.
18
Which type of inhibition does not alter the Km value?
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(B)
Noncompetitive inhibition
19
Which of the following enzyme levels increases in obstructive jaundice?
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C
D
20
Which of the following statements is correct regarding enzyme inhibitors?
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A
C
D
21
How does a competitive inhibitor affect the reaction rate?
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(D)
It can increase or decrease the rate, depending on the substrate concentration.
22
What does the Lineweaver-Burk plot is used for?
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(C)
To determine Vmax and Km values.
23
What is the general role of an isomerase?
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(C)
To catalyze the rearrangement of atoms within a molecule.
24
Enzymes may be used as the following, except:
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(D)
Nutrients
25
What are the common clinical applications of measuring LDH isoenzymes?
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(D)
All of the above
26
How do allosteric enzymes regulate biochemical pathways?
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(C)
By being regulated by modulators
27
Which type of inhibitor affects both the Km and Vmax of an enzyme?
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(C)
Uncompetitive
28
Which inhibitor type results in a decrease in both the Km and Vmax?
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(C)
Uncompetitive inhibitor
29
Which of the following is used in the treatment of some types of leukemia?
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(B)
Asparaginase
30
Which enzyme is useful for dissolving fibrin clots?
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(C)
Streptokinase
31
Which type of enzyme is involved in the transfer of phosphate groups?
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(B)
Transferase
32
The 'lock and key' model explains that the enzyme and substrate:
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(A)
Fit perfectly together.
33
What would be the effect of a non-competitive inhibitor on a Lineweaver-Burk plot?
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(A)
The y-intercept changes and the x-intercept remains the same.
34
Which of the following enzyme classifications catalyze the formation of bonds with the input of ATP?
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(B)
Ligases
35
The Michaelis constant (Km) is:
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(C)
The substrate concentration at 1/2 Vmax
36
What is a common clinical application of measuring lipase?
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(C)
Diagnosis of pancreatitis
37
What is the role of alkaline phosphatase in clinical diagnosis?
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(A)
Diagnosis of liver disease and bone disorders
38
What is the effect of an irreversible inhibitor on an enzyme?
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(B)
It permanently inactivates the enzyme.
39
In which type of enzyme inhibition does the inhibitor bind to a site distinct from the active site, but changes the shape of the active site?
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(B)
Non-competitive inhibition
40
Enzyme activity in biological systems may be affected by the following:
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A
B
C
D
41
Which of the following enzymes is classified as a hydrolase?
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(C)
Amylase
42
Liver diagnostic enzyme is:
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(C)
Alanine transaminase
43
What does Vmax represent?
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(B)
The maximum reaction rate.
44
Which enzyme is elevated in urine in the patient of acute pancreatitis?
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(A)
Amylase
45
What is the normal serum value for adult of Alkaline phosphatase (ALP)?
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(C)
13 to 100 U/L
46
Which of the following can affect enzyme activity?
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A
B
C
D
47
Which enzyme, elevated in serum, is used for diagnosis of acute myocardial infarction?
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(B)
Creatine Kinase (CK-MB)
48
Which of the following is a characteristic of uncompetitive inhibitors?
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(B)
They bind only to the enzyme-substrate complex.
49
What is the primary function of the enzyme amylase?
